Influence of speed-related auditory feedback on braking in a 3D-driving simulator

International audienceAlthough discrete auditory stimuli have been found useful for emergency braking, the roleof continuous speed-related auditory feedback has not been investigated yet. This pointmay though be of importance in electric vehicles in which acoustic cues are drasticallychanged. The present study addressed this question through two experiments. In experi-ment 1, 12 usual drivers were exposed to naturalistic auditory feedback mimicking thoseissued from electric cars, while facing dynamic visual scenes in a 3D driving simulator.After being passively travelled up to a sustained constant speed, subjects had to stop theircar in front of a traffic light that unexpectedly turned to red. Modifications of the speed-related auditory feedback did not impact braking initiation and regulation. In experiment2, synthesized auditory feedback based on the Shepard-Risset glissando was provided to anew sample of 15 usual drivers in the same task. Pitch variations of this acoustic stimulus,although not scaled to an absolute speed, were manipulated as a function of visual speedchanges. Changing the mapping between pitch variations of the synthesized auditory feed-back and visual speed changes induced adjustments on braking which depended on accel-eration/deceleration feedback. These findings stressed the importance of the acousticcontent and its dynamics for car speed control